[Nemo de Monet]

Hmmn, I used to get updates when people posted to this ancient thread, but not any more.
 
I'm not sure where you're measuring 24VDC at, so it's hard to guess what's wrong. You don't have the LM317s in backwards or something, do you? Did you include the LED? Are you measuring with the tube in the socket? Also, what variety of 2SK117 did you go with? I think you might run into problems if you're using the -Y or -GR versions.
 
I'm one of those who tried a 1000uf cap for C103, the power reservoir, and one of those who maintains that's undersized. That said, there have been so many variations made of this design, with so many different components, that it's easily possible for pretty much any definitive statement to be disproved...

 

[lehtinel]

I started building mine today. Still missing heatsinks, a couple of resistors and such, but should have all parts by next week.
 
This will be interesting to build and use after the Cmoy that was my first (been happy with that at work for little over half a year now). My configuration will be Elna Silmic II 1000uf caps on C103 and C102/202, I have 220uf/50v Silmic II:s for the C104/C105 spot too, but they won't fit in there, guess I will go for basic low-ESR caps here, any comments on the C104/105 cap choice?
 
For C101/C201 I've got Wima 0.1uf, Solen Fast 1.0uf and Icel 1.0uf caps, guess I'll tinker about and see what sounds best (once i've got the thing running). My current tube is a cheap 12AX7 tube from my guitar amp, will probably change this once I've confirmed I have a working amp.

 

[jamesbobo007]

I had the same issue with C104/105. In my case, I was able to put in new holes for the pads of C104 a bit closer to R106. Worked for me, Here is a pic of my C104/105 http://i592.photobucket.com/albums/tt8/jamesbobo/6DJ8%20amp/JD8caps.jpg
My other plan was to add a thru hole in the void area to the left of R203 and R209,for the Negative lead, bring it under the board back to the (-) pad and use the (+) pad as is. If you look at the pic of the board on page 2, 2nd post, it should make sense.
3rd plan was to just leave it up in the air and bend the leads, there is plenty of vertical room !
 
Enjoy !
 
 

 

[lehtinel]

Quote:

I had the same issue with C104/105. In my case, I was able to put in new holes for the pads of C104 a bit closer to R106. Worked for me, Here is a pic of my C104/105 http://i592.photobucket.com/albums/tt8/jamesbobo/6DJ8%20amp/JD8caps.jpg
My other plan was to add a thru hole in the void area to the left of R203 and R209,for the Negative lead, bring it under the board back to the (-) pad and use the (+) pad as is. If you look at the pic of the board on page 2, 2nd post, it should make sense.
3rd plan was to just leave it up in the air and bend the leads, there is plenty of vertical room !
 
Enjoy !
 
 

Hmm...wouldn't it be possible to use the R106 + hole for the C104 cap. They are in the same line and if I am correct R106 is for the led only (which Im planning to skip anyhow). Would this work?

 

[jamesbobo007]

I see what your thinking but I dont think it will solve it, you wouldnt be increasing the space between the (-) legs of C104/105, which is where I had my size issue.
But dude,,,no led ??  what good is a tube if you cant see it glow ? LOL
Really, just get it running, clean it up later if you want.

 

[lehtinel]

Quote:

I see what your thinking but I dont think it will solve it, you wouldnt be increasing the space between the (-) legs of C104/105, which is where I had my size issue.
But dude,,,no led ??  what good is a tube if you cant see it glow ? LOL
Really, just get it running, clean it up later if you want.

Haha, I know, Im crazy, maybe I'll just stick in the small low-esr caps I'll get next week for C104/105 and put a BRIGHT led under the tube instead. We'll see, thanks for the input!

 

[lehtinel]

 
 
They do sit on the board by sacrificing the led resistor. R109 should just fit in there, it being a 1/4w resistor.
 

 

[jamesbobo007]

Awesome fix !
 

 

[lehtinel]

Quote:

Awesome fix !
 

Well, you got me into it so...the thanks go to you

 
Coupling caps arrived today, Solen Fast 1.0uf just snugly fitted in place. Minor soldering done today (aaah, holiday), waiting for heatsinks and the rest of the resistors, here tomorrow maybe.
 

 

[lehtinel]

Got the last parts on Tuesday, smaller heatsinks than I was expecting, I have some more, larger, coming in later, so I'll change them out. Other than that everything seems okay.  I didn't have time to connect input, output and volume pot before leaving on holiday. I connected my 24v 2.5A power supply to the board, but couldn't get any reading when measured from the PCB. The power supply itself gave out 23.8V measured from the input socket. 
 
Any ideas? Should the board power up or does it have something to do with the pot missing maybe? 
 
Well, no panic, ran out of time and will get back to the project next week when I get home again.

 

[Nemo de Monet]

Were you trying to measure voltages without a tube in place? That generally doesn't work on this design.

 

[lehtinel]

Quote:

Were you trying to measure voltages without a tube in place? That generally doesn't work on this design.

 
I've got the tube in place but still my measurements are at 0v all over the place. The PS gives out the correct voltage when not connected to the board. As soon as I hook it up Im at 0v. I should have time to solder the pot + input and output in place today, maybe that will change things.
 
I can't see direct flaws in my build, other than leaving R106 + the LED out of the equation. You never know though
 
 

 

[lehtinel]

There seems to be an issue with my power supply. I can't get a reading from it now, it's brand new with short circuit and overload protection so I don't now what is up with it. Dont have any other 24v PS hanging around, tried an 12v / 1A PS and that gave a reading at the power input and behind the fuse.
 

 

[jamesbobo007]

This wont explain your wacky voltage readings, but where is your power switch for the amp?
 

 

[lehtinel]

Quote:

This wont explain your wacky voltage readings, but where is your power switch for the amp?
 

Not installed yet as Im not sure with the casing (the eddystone / hammond crule aluminium casing is teporary or a shell for someting nicer), I have one handy though. The jack is now directly wired to the board.